Can dogs and cats eat Hydrangea?

If you think your pet has been poisoned

If you suspect your dog or cat has eaten or touched something poisonous, contact your vet or the nearest emergency veterinary clinic immediately, even if your pet seems fine – some poisons take hours or days to show signs, and early treatment works best. Do not try to make your pet vomit unless a vet tells you to, as this can cause more harm. Take the packaging, label or a piece of the plant with you, and note what was eaten, roughly how much, and when.